Development and Testing of a Multisensor Integrated Device for Reservoir Landslides Hydro-Fluctuation Zone

The stability of reservoir landslides is significantly influenced by the hydraulic fluctuations in the hydro-fluctuation zone. However, integrated devices capable of simultaneously monitoring the deformation of landslides and the fluctuations of reservoir water levels in this zone are still unavailable. To address this, a multisensor integrated device (MSID) has been developed for real-time observation of the hydro-fluctuation zone of reservoir landslides in this study, incorporating functions such as cross-media ranging, landslide surface attitude alterations measurement, water level monitoring, and wave activity tracking. The radar sensor based on stepped-frequency continuous wave (SFCW) was adopted for the cross-media ranging across the air-water interface for the first time, and the corresponding computing method was also provided. Besides, a six-axis inertial measurement unit (IMU) and a piezoresistive level sensor were also integrated into the device for the monitoring of attitude alterations and changes in the reservoir hydrological environment. The test results show that the developed device is effective in ranging across the air-water interface, showing a high linear correlation between measured and actual distances under various water depths, with the best $R^{2}$ being 0.9734 and a maximum range of 1.216 m at a water depth of 0.6 m. Also, the attitude alterations measurement demonstrates exceptional measurement precision for roll, pitch, and yaw angles with the best $R^{2}$ infinity approaching 1. Furthermore, the device can accurately observe the water level as well as the frequency and amplitude of waves under both still water and wave conditions.